The present invention relates to an antenna for use in a mobile terminal and specifically to a patch antenna structure that serves a dual purpose within the mobile terminal.
First there were pagers, then wireless phones, and more recently, personal digital assistants. Recent events have led to a convergence of these devices under the general appellation of a mobile terminal. Common to these devices in the latest generation is the ability to communicate wirelessly with a remote location.
These mobile terminals are becoming ubiquitous throughout the world. While telecommunication standards may vary from country to country, the wireless revolution is in full swing. Mobile terminals can now be seen almost everywhere, and are becoming the pervasive computing devices envisioned.
Since the initial car and bag phones were introduced, there has been constant pressure on the part of mobile terminal manufacturers to make the mobile terminals smaller. Keypads, batteries, and electrical components have all been reduced in size to make mobile terminals with smaller profiles.
One area that historically has been resistant to changes in size is the antenna of the mobile terminal. This has been due to the need to isolate the antenna from other sensitive electronic components within the mobile terminal from cross talk and other electromagnetic compatibility issues. For example, positioning an antenna close to the electronic components may cause spurious emissions exceeding allowable FCC standards.
A concurrent trend in the mobile terminal industry is to modularize components such that only a few modules contain all of the electrical components for the mobile terminal. Coupled with this modularization effort are efforts to integrate the electrical components into a single chip such that manufacturing costs are decreased.
Heretofore, efforts to remove the traditional stub antenna and integrate an antenna into the body of the mobile terminal have failed.
The present invention enables an antenna to be integrated within the body of a mobile terminal. Specifically, the present invention takes advantage of a ground plane structure that dissipates eddy currents and isolates a patch antenna from spurious electromagnetic signals. This structure then forms a substrate for other electrical components, such as those that comprise a transceiver front end for the mobile terminal.
In one embodiment, the antennas include a kink to increase the electrical length thereof and to perform impedance matching.